• Corneal collagen cross-linking
• CXL
• keratoconus
• riboflavin
• UVA
• cornea

Corneal collagen cross-linking (CXL) is a novel technique for increasing corneal tissue strength and rigidity, which involves polymerisation of stromal fibres by the combined action of the photosensitiser riboflavin (vitamin B₂) and ultraviolet A (UVA) rays.1 The main indication for CXL in the ophthalmology arena has been the management of corneal ectasia, such as halting the progression of keratoconus.2 In addition, CXL has been proposed as a treatment modality for iatrogenic keratectasia,3 infectious corneal ulcers,4 bullous keratopathy5 and progressive myopia.6 CXL is the only available treatment that is directed to treat the underlying pathology in keratoconic corneas, which is stromal imbalance. Since its introduction, other surgical procedures, such as topography-guided photorefractive keratectomy (PRK), intracorneal rings and phakic intraocular lens (IOL) surgery, are being added to CXL to correct the visual consequences of keratoconus.7 Lorelei and Boxer Wachler in this issue (see page 1597) have carried out a study in which they showed that Intacs and crosslinking on the same day as an approach to treat keratoconus benefited most those patients with worse best-corrected visual acuity and spherical equivalent to gain a greater postoperative best-corrected visual acuity improvement.8 This may be helpful in comprehensive counselling during the initial evaluation.

Due to the corneal epithelial tight junctions resulting in incomplete penetration of riboflavin macromolecules, the standard procedure starts with abrasion of the corneal epithelium out to 7–8 mm, under topical anaesthesia. The de-epithelisation exposes the …